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I tried to do the loss of vent air flow to the defrost vents fix and so far it didn’t work. I pulled the vacuum intake line into the cab, and pulled through the old reservoir line into the cab, hooked up a check valve and a few Dorman reservoirs. There’s zero improvement. Any ideas?
I believe the fix you did is supposed to be for when the air ONLY goes to the defrost vents but you started by saying you couldn't get the defrost position. Which issue are you troubleshooting??
In any case, attached is the Service Manual info for the climate control vacuum system.
Thank you for the diagrams. I was referring to the common problem with econoline where otherwise the AC/Airflow is operating normally except when the vehicle is under acceleration.
under acceleration the airflow will automatically redirect from the vents to the defrost.
also, my vacuum connector doesn’t seem to match the diagram posted.
The photo in your last post appears to be for some inline connector. The diagram I posted is, I believe, for the plug onto the back of the control selector.
Since the vacuum in the system drops when the throttle is opened, once the resulting component is where it is supposed to be, vacuum just holds it there.
What is needed is a check valve that will allow vacuum to build, but not to drop as the throttle is opened.
If the check valve is placed in the line to the vacuum reservoir, it will prevent the vacuum from dropping . If there is a check valve in the line from the intake to the reservoir it is not functioning. If there isn't one there, purchase one and install it in the vacuum line to the reservoir. Just make sure it is installed in the right direction , it will work only one way. Let us know how you make out with this, thank you.
2006 E250 Accelerator fix gone bad.
